Refractive Errors

Refractive Errors

Emmetropia – When the shape of the cornea is normal, visual images are focused directly on the retina. This condition is called emmetropia. A patient with emmetropia will not have difficulties focusing on objects at any distance. Emmetropia does not require refractive treatment.

Myopia – When the cornea is too steep, visual images are focused in front of the retina. This condition is called nearsightedness or myopia. A patient with myopia will be unable to see objects at a distance. Treatments include glasses, contact lenses, or refractive surgery.

Hyperopia – When the cornea is too flat, visual images are focused behind the retina. This condition is called farsightedness or hyperopia. A patient with hyperopia will be able to see objects at a distance, but will have trouble focusing on objects up close. Treatments include glasses, contact lenses, or refractive surgery.

Astigmatism – When the cornea is curved more in one direction than another, visual images will not be focused properly. This condition is called astigmatism. A patient with astigmatism will have difficulties focusing on objects at any distance and may experience eye strain and headaches. Treatments include glasses, contact lenses, or refractive surgery.

Presbyopia – When the lens of the eye loses its flexibility, visual images will not be focused properly. This condition occurs around the age of 40 and is called presbyopia. A patient with presbyopia will have difficulty focusing on objects up close. Treatments for presbyopia include glasses (bifocals), contact lenses (bifocal or monovision), or monovision refractive surgery.